Abstract : Flow-induced vibrations of Steam Generator (SG) tube bundles are a major concern for the operators of nuclear power plants. In order to predict damages due to such vibrations, EDF has developed the numerical tool GeViBus, which allows one to evaluate safety margins and thereafter to optimize the SG maintenance policy. The software is based on a semi analytical model of fluid-dynamic forces and dimensionless fluid force coefficients which need to be assessed by experiment. The database of dimension-less coefficients is steadily updated in order to cover all tube bundle configurations found in EDF power plants. Within this framework, we present a new test rig dedicated to the parallel triangular tube arrangement submitted to a two-phase cross-flow. A new test loop is constructed as well, allowing fluid-elastic instability to be induced on the test rig for various qualities. The details of the experimental arrangement are presented together with the preliminary validation tests.